June 07, 2007

Elephant feet pick up the signal

Elephants don't need to put their ear to the ground to hear far-away sounds. They can just use their feet.

A report in New Scientists say it's a common practice, but elephants react most if the calls they hear come from elephants they know.

Elephants are already known for their ability to emit low-frequency
sounds to communicate with herds up to several miles away.

Researchers led by Caitlin O'Connell-Rodwell of Stanford University
Medical Center in California also suspected that these rumblings
generate seismic waves that travel through the ground, enabling
elephants to pick up the signals through their surprisingly sensitive
feet.

Her team recorded alarm calls in Namibia and Kenya made by elephants when lions were lurking.

They then played just the seismic portion of the sound through the ground to herds at watering holes in Namibia.

The elephants "reacted dramatically, first freezing and then clumping
in tight groups, with babies in the middle," the British weekly reports
in next Saturday's issue.

But the farther the elephants lived from the herd which made the call, the less they reacted.

The study is to be published in the Journal of the Acoustical Society of America, New Scientist says.photo:AFP/DDP/Marcus Brandt